diff --git a/src/components/CopyButton.tsx b/src/components/CopyButton.tsx
new file mode 100644
index 0000000..cea585f
--- /dev/null
+++ b/src/components/CopyButton.tsx
@@ -0,0 +1,37 @@
+import { useState, useCallback } from "react";
+import { VARIANT_CLASSES } from "./badge-utils";
+
+// Copy-to-clipboard pill, styled to match the analyzer's "Copy Link" button: flips to a green
+// "Copied" state for 1.5s after a click. aria-label defaults to the visible label.
+export function CopyButton({
+  value,
+  label = "Copy",
+  copiedLabel = "Copied",
+  ariaLabel,
+  className,
+}: {
+  value: string;
+  label?: string;
+  copiedLabel?: string;
+  ariaLabel?: string;
+  className?: string;
+}) {
+  const [copied, setCopied] = useState(false);
+
+  const handleCopy = useCallback(() => {
+    navigator.clipboard.writeText(value);
+    setCopied(true);
+    setTimeout(() => setCopied(false), 1500);
+  }, [value]);
+
+  return (
+    <button
+      type="button"
+      className={`inline-flex items-center font-mono text-[11px] font-semibold px-2 py-0.5 rounded-sm border tracking-wider uppercase cursor-pointer transition-colors ${copied ? VARIANT_CLASSES.live : VARIANT_CLASSES.text} ${className ?? ""}`}
+      onClick={handleCopy}
+      aria-label={ariaLabel ?? label}
+    >
+      {copied ? copiedLabel : label}
+    </button>
+  );
+}
diff --git a/src/features/nodes/NodeDetailPanel.tsx b/src/features/nodes/NodeDetailPanel.tsx
index 7dba588..57a62e0 100644
--- a/src/features/nodes/NodeDetailPanel.tsx
+++ b/src/features/nodes/NodeDetailPanel.tsx
@@ -2,6 +2,7 @@ import { useQuery } from "@tanstack/react-query";
 import { getNode, getNodeObservations, getNodeNeighbors } from "../../api/client";
 import { Badge } from "../../components/Badge";
 import { DetailPanel, Section, Field } from "../../components/DetailPanel";
+import { CopyButton } from "../../components/CopyButton";
 import { IataChip } from "../../components/IataChip";
 import { formatHex, formatSnr, snrLevel, formatRadio, SIGNAL_LEVEL_CLASSES } from "../../lib/formatters";
 import { Timestamp } from "../../components/Timestamp";
@@ -116,8 +117,11 @@ export function NodeDetailPanel({ nodeId, onClose, onViewObserver, onViewNode, o
                 </span>
                 <Badge variant="default">{node.nodeTypeName}</Badge>
               </div>
-              <div className="font-mono text-[13px] text-text-muted truncate" title={node.publicKey}>
-                {node.publicKey}
+              <div className="flex items-center gap-2">
+                <div className="font-mono text-[13px] text-text-muted truncate min-w-0 flex-1" title={node.publicKey}>
+                  {node.publicKey}
+                </div>
+                <CopyButton value={node.publicKey} ariaLabel="Copy public key" className="shrink-0" />
               </div>
               {node.observerId && (
                 <button
diff --git a/src/features/observers/ObserverDetailPanel.tsx b/src/features/observers/ObserverDetailPanel.tsx
index 9c3f48f..3c33bab 100644
--- a/src/features/observers/ObserverDetailPanel.tsx
+++ b/src/features/observers/ObserverDetailPanel.tsx
@@ -3,6 +3,7 @@ import { useQuery } from "@tanstack/react-query";
 import { getObserver, getObserverAdverts } from "../../api/client";
 import { Badge } from "../../components/Badge";
 import { DetailPanel, Section, Field } from "../../components/DetailPanel";
+import { CopyButton } from "../../components/CopyButton";
 import { formatUptime, formatBattery, formatHex, formatSnr, snrLevel, SIGNAL_LEVEL_CLASSES } from "../../lib/formatters";
 import { Timestamp } from "../../components/Timestamp";
 import { useTick } from "../../hooks/useTick";
@@ -145,8 +146,11 @@ export function ObserverDetailPanel({ observerId, onClose, onAnalyzePacket, onVi
                   {status}
                 </Badge>
               </div>
-              <div className="font-mono text-[13px] text-text-muted truncate mb-1.5" title={observer.publicKey}>
-                {observer.publicKey}
+              <div className="flex items-center gap-2 mb-1.5">
+                <div className="font-mono text-[13px] text-text-muted truncate min-w-0 flex-1" title={observer.publicKey}>
+                  {observer.publicKey}
+                </div>
+                <CopyButton value={observer.publicKey} ariaLabel="Copy public key" className="shrink-0" />
               </div>
               <div className="flex items-center gap-3 font-mono text-[13px]">
                 <Field label="Observations" value={observer.observationCount.toLocaleString()} />
diff --git a/tests/components/CopyButton.test.tsx b/tests/components/CopyButton.test.tsx
new file mode 100644
index 0000000..3d5fb4a
--- /dev/null
+++ b/tests/components/CopyButton.test.tsx
@@ -0,0 +1,49 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent, act } from "@testing-library/react";
+import { CopyButton } from "../../src/components/CopyButton";
+
+const writeText = vi.fn();
+
+beforeEach(() => {
+  Object.defineProperty(navigator, "clipboard", {
+    value: { writeText },
+    writable: true,
+    configurable: true,
+  });
+  writeText.mockClear();
+});
+
+describe("CopyButton", () => {
+  it("shows the default 'Copy' label", () => {
+    render(<CopyButton value="deadbeef" />);
+    expect(screen.getByRole("button")).toHaveTextContent("Copy");
+  });
+
+  it("writes the full value to the clipboard on click", () => {
+    const key = "0123456789abcdef0123456789abcdef";
+    render(<CopyButton value={key} />);
+    fireEvent.click(screen.getByRole("button"));
+    expect(writeText).toHaveBeenCalledWith(key);
+  });
+
+  it("swaps to 'Copied' after clicking, then reverts", () => {
+    vi.useFakeTimers();
+    try {
+      render(<CopyButton value="deadbeef" />);
+      const button = screen.getByRole("button");
+      fireEvent.click(button);
+      expect(button).toHaveTextContent("Copied");
+      act(() => {
+        vi.advanceTimersByTime(1500);
+      });
+      expect(button).toHaveTextContent("Copy");
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
+  it("uses the provided aria-label for the accessible name", () => {
+    render(<CopyButton value="deadbeef" ariaLabel="Copy public key" />);
+    expect(screen.getByRole("button", { name: "Copy public key" })).toBeInTheDocument();
+  });
+});